Connect to a Public Wireless Network

The point of wireless networking
is not necessarily to do away with a few feet of cables, but to make
a network do things it could never do before. For instance, if you
have a portable computer equipped with wireless, you should be able
to walk into any airport, coffee shop, hotel, or college dormitory
and connect to the Internet in a matter of seconds. In more populated
areas, it's not uncommon to walk down the street and
have your pick of WiFi networks. (See the sidebar for an extra
consideration.)

The Ethics of WiFi

Once you get the technical details out of the
way, the one remaining hurdle when
considering using someone else's Internet connection
is a question of ethics. There are countless personal wireless
networks around the globe, and most of them, you'll
find, are unsecured. This means that you can literally walk down the
street in a populated area and probably find a working wireless
Internet connection before you reach the end of the block. Some will
have been left open intentionally, but most will be unsecured merely
because their owners don't have the benefit of the
Section 7.5.1 procedure detailed
earlier in this chapter.

Now, just because you can connect to these networks, does it mean you
should? Are you taking advantage of someone else's
ignorance by breaking into their private network, or are you simply
making use of a public resource that you'd be
equally eager to share?

I'm not about to try to solve this dilemma in these
few pages; I only wish to raise the question, and to suggest that if
you do ever decide to utilize someone else's
wireless network, do not do any harm. Think about your impact, both
on the bandwidth of the foreign network and the privacy of those who
operate it. And then tread lightly.

As described in Section 7.5.2
earlier in this chapter, you can connect to any unsecured wireless
network that Windows XP's built-in WiFi sniffer is
able to detect. (The exceptions, of course, are those networks
requiring a paid subscription or account access, but
that's a different story.) This applies to networks
you encounter while you're on the road, as well as
those that are in range of your home or office.

Router Placement 101

The tiny WiFi transceiver in your laptop should be
capable
of picking up any wireless network within about 100 feet. If indoors,
this typically includes no more than about 2 or 3 walls, and perhaps
one floor or ceiling. But the placement of your wireless router and
the arrangement of natural obstacles near it will have a significant
effect on the strength and range of your WiFi signal.

Assuming you're using a setup like the one pictured
in Figure 7-6, your router will need to be within
spitting distance of your DSL or cable modem. But provided that the
cable from your modem to your router is long enough, you should have
a little leeway here.

Your router should be out in the open; don't put it
under your desk, in a drawer, or behind a metal file cabinet. If
you're feeding more than one computer, it should be
placed in a central location, if possible. Use the signal strength
indicator (Figure 7-10) to test various
configurations. Consider cabling stationary computers so that you can
optimize the placement of the router for your portable ones.

Both the 802.11b and 802.11g standards operate
over the 2.4Ghz band, which is also inhabited by cordless phones and
microwave ovens. (The black sheep of the family,
802.11a solves this
problem by using the 5Ghz band, but its short range and limited
compatibility make it an unpopular choice.) This means that
you'll get better results if you move the router
away from any cordless phone base stations, televisions, radios, or
TV dinners.

If, after adjusting the placement of your router, you still need more
range that it seems to be able to provide, consider either a repeater
(range extender) or an aftermarket antenna.

The problem is that by connecting to these networks,
you're exposing your computer to the full array of
viruses, hackers, and other dangers present on any network.
[3]
The solution is to take action to protect your computer
(or workgroup), and the necessary steps depend on the scenario.

Scenario 1: Single-Serving Internet

Say you've just sat yourself down at a sidewalk
cafe, and pulled out your laptop. (This scenario also applies to
hotel rooms, airports, and coffee shops.) You boot up Windows, open
the "Choose a wireless network"
window as described in Section 7.5.2, find a local
network, and connect for approximately 20 minutes to check your
email. When you're done, you'll
likely never use this network again.

Now, if you typically use your laptop from behind a wireless router
at home (as described in Section 7.5.1 earlier in this chapter),
you'll want to take some extra steps to secure your
computer before you connect elsewhere. Since you
won't have your router with you on the road, and
thus won't have any dedicated firewall hardware,
you'll want to employ the built-in Windows Firewall
software (or a third-party firewall solution), as described in Section 7.6.2 later in this chapter. This
will provide minimal protection, insufficient for the long haul.

Scenario 2: The Long Haul

Say you just moved into an apartment complex (or have a small
business in an office building) that provides free wireless Internet.
Naturally, you would never want to connect your computer or workgroup
to this wireless free-for-all without some sort of reliable,
long-term firewall solution. Now, since this is not your own private
Internet connection, you can't just plug in a router
to facilitate your firewall. But you can add another device, a
wireless bridge, in order to build an
"island" of sorts, in a sea
otherwise filled with danger.

Figure 7-24 shows a sample setup involving a
wireless bridge and a router. The two dotted rectangles represent the
scope of the two different WiFi networks in effect: your own private,
encrypted wireless network is shown on the right, and the public
network is illustrated on the left. (Your bridge and router actually
form a tiny, third network, complete with its own set of IP addresses
separate from those in either of the two wireless networks.)

Figure 7-24. Use a wireless bridge in conjunction with a wireless router to protect your workgroup when connecting to a public Internet connection

WARNING
This can be tricky to set up, and may require some trial and error to
get it right. Depending on your specific hardware and your needs, you
may need to adjust this procedure somewhat. For the simplest setup,
make sure your bridge and router are manufactured by the same
company.

Here's how you set it up:

Obtain a
wireless
bridge, and follow the procedure laid out in its documentation to set
it up with the aforementioned public wireless network. (This
typically involves plugging it directly into your PC or one of the
numbered ports of your router.) While you're here,
obtain the IP address of your bridge; it'll be
something like 192.168.1.1 or
192.168.0.1.

When you're done setting up the bridge, connect it
directly to the WAN port of your wireless router. (This is the port
into which you'd normally plug a DSL or cable
modem.)

Configure your wireless router so that it has a Connection Type of Static IP. (Refer to your
router's documentation for the specific details on
this and the next few settings.)

In the router setup, set the Gateway
address to the IP address of your bridge that you obtained in step 2.

Then, set the IP address of the Internet connection (as the router
sees it) to a fictitious IP address in the same
subnet as your bridge. This means that the
first three numbers of both IP addresses should
be the same, but the fourth should be different. That is, if your
router is located at 192.168.1.1, then you could
set the IP address of your Internet connection to something like
192.168.1.2 or 192.168.1.73.

Finally, set the DNS server addresses in your router setup to the IP
addresses of your Internet Service Provider's DNS
servers.

TIP:
If you don't know what Internet Service Provider
you're using, connect your PC directly to the
wireless network in question. Open a web browser, type http://annoyances.org/ip in the address bar,
and press Enter; this will show the
IP address of your Internet connection. Then, open a Command Prompt
window (see Chapter 10) and type nslookupip_address, where
ip_address is the set of four numbers
reported by Annoyances.org. This should give you the name of your
ISP, plus some extra stuff. So, you might see something like
dsl456.eastcoast.superisp.net, which means your
ISP is
"superisp.net."
Then, it's only a matter of visiting their web site
and determining their DNS server addresses from their online
documentation!

This should do it. The bridge funnels the public Internet connection
into your router, and your router funnels it to the computers in your
workgroup. The router acts like a firewall, provided that you connect
all your computers directly to your personal WiFi network, and not
the public, unsecured one.

Among other things, your bridge/router combination will serve as a
repeater (aka range extender), and should boost the signal strength
and might even improve performance over connecting
directly.

Add Wireless Support to Any Device

As soon as you have your wireless
network up and running, you'll probably be inclined
to do away with as many cables as you can. This feeling is normal;
there's no need to seek psychiatric help or psychic
guidance.

There are ways to add support for wireless networking to nearly any
computer or device, further illustrating what you can do with a
wireless network:

Desktop computer

Add a wireless PCI card just as you would an Ethernet NIC (network
interface card). When shopping for a WiFi NIC, look for a card with
an adjustable, external antenna (versus merely a nub.) Another
alternative is a USB-based WiFi adapter, which will be easier to
install, but probably at the expense of some performance.

Laptop computer

Printer

TiVo

One of the biggest hassles of using a Digital Video
Recorder (DVR) is that you need to connect it to a phone line so that
it can download the latest program data. If you have a newer DVR
(such as Series-2 TiVo) that comes with built-in networking support,
you can use a USB-based WiFi adapter and finally cut the cord. If you
have an older Series-1 TiVo, you'll need to add a
TurboNet card (available at http://www.9thtee.com/) and then connect that
to an external WiFi bridge. Alternatively, you can use a
AirNet card (also available at http://www.9thtee.com/) along with a PCMCIA
802.11b adapter you provide, but its range will be more limited than
the aforementioned bridge. See TiVo Hacks
(O'Reilly) for more ways to modify your TiVo.

Video Game Console

Own a Playstation2, XBox, or other network-capable
video game console? Just plug a wireless
bridge (sometimes called a wireless game adapter) into your
console's Ethernet port, and play head-to-head games
without the network cables stretched across your living room.

Handheld PDA

As introduced in the beginning of this chapter, there are two
prevailing wireless technologies: WiFi and Bluetooth. While some
handhelds come with built-in WiFi, a larger percentage support
Bluetooth (and only a select few play for both teams). Although only
WiFi-equipped handhelds can connect to the WiFi networks discussed
throughout this chapter, you'll need Bluetooth
support if you want to connect to the Internet with your
Bluetooth-equipped cell phone. (The same goes for laptops; get an
inexpensive Bluetooth USB dongle to connect your Windows PC to your
cell phone wirelessly and surf the web from the park or even the
train!)

Now, some higher-end PDAs come with WiFi or Bluetooth support built
in, while others have special expansion cards that provide
connectivity. You can get a WiFi SecureDigital (SD) card or a
Bluetooth
SD card that will fit in many PalmOS and PocketPC handhelds, but if
you only have one SD slot, you'll have to remove
your memory card. If you need the wireless support, you may prefer to
replace your PDA with one that has WiFi or Bluetooth (or both) built
in, and do away with the awkward protrusion of the expansion card.

Digital camera

Some high-end digital cameras now have WiFi options,
allowing you to send your photos to the hard disk of a nearby
computer wirelessly, either in batches or immediately after you take
them. Unfortunately, this only works in the studio (as opposed to
outdoors), where you'd be in range of your wireless
router. At the time of this writing, there are no wireless cards you
can conveniently insert in place of your digital film, but it
shouldn't be long.

Video camera (webcam)

Home stereo

Several companies sell
WiFi music players that connect your
MP3 collection on your computer to your component stereo system and
allow you to hear your music on something better than the tinny
computer speakers you're likely using now.

Car stereo

At the time of this writing, a WiFi-enabled MP3 player in your car is
only vaporware, but keep your eyes open. Soon, manufacturers promise
us, you'll be able to send digital music to your car
wirelessly. I can't wait for my car stereo to catch
an airborne virus.

There's virtually no limit to the number of devices
you can make wireless, provided that they support some form of
networking already. If all else fails, a wireless bridge, as
illustrated in Section 7.5.3,
earlier in this chapter, should allow you to connect just about
anything to your wireless network.